LONDONERS could be more than 40 minutes from specialist medical units designed to treat the most seriously injured patients, experts fear.

Only three hospitals in the capital have been judged good enough to become "major trauma centres".

These hospitals to which the seriously ill, as well as casualties of gun and knife crime and major road accidents, would be taken directly were meant to be spaced evenly across London.

Healthcare for London - the organisation behind the centres - pledged that 99.5 per cent of patients would be able to get to them within 40 minutes.

But fears have been raised that the target is unrealistic for people in most of the north of the capital.

Consultant Andrew Hobart, who chairs the British Medical Association's emergency medicine sub-committee, said: "There are parts of north-west and north central London that are unlikely to be within 40 minutes of one of the centres, even in a blue-light ambulance.

"There is some anxiety about having only three. What happens if one is the site of a major incident and is out of action? Only having three makes us pretty vulnerable." However, Mr Hobart said it would be better to travel for up to an hour to a proper major trauma centre than to a local hospital that did not have the correct facilities.

A consultation on the plan will take place next month. The hospitals that have been approved are the Royal London in Whitechapel, King's College in Camberwell and St George's in Tooting.

Bosses rejected the Royal Free in Hampstead and Imperial College healthcare trust, which runs Hammersmith Hospital in Shepherd's Bush, Charing Cross Hospital in Hammersmith, and St Mary's in Paddington.

A Healthcare for London spokeswoman said those turned down "were judged not to have met the clinical standards that are in place to reach the level by 2010".

But she added: "This is not an indication of the clinical quality within A&E departments. Major trauma centres will provide a more complex service including neurology, orthopaedics, and vascular surgery on one site." The centres will also perform emergency brain surgery and complex bone operations such as pelvic reconstruction after a car crash. Health bosses believe 40 per cent more major trauma victims could be saved.